Enhancing Data Reproducibility Through Cell Authentication Training aims to create an exportable online training module on cell authentication suitable to all postgraduate researchers who use cell lines in their research, including graduate students, postdoctoral scholars, and junior faculty members. NIH currently funds approximately 9,000 projects and sub-projects involving cell lines, at a total spend of $3.7B. While the National Cancer Institute funds the bulk of these projects, all Institutes at the NIH and the FDA fund studies using cell lines. Cell line contamination and misidentification are major contributors to research reproducibility problems. Best practices exist to reduce these problems significantly and ensure more effective use of research dollars, and yet awareness and implementation of these practices remain low. We believe that an effective active learning training module and robust dissemination campaign will improve both awareness and implementation. This module will contain highly interactive training units including how to videos that will turn learning into practice by sending the trainees back into the laboratory to practice their skills, and tracking whether their training is incorporated into their future researh. We will build partnerships and develop social media strategies to disseminate and promote this module to all postgraduate researchers who use cell lines in their work. The module will be optimized for use both by individuals accessing the material directly in an online-only format, and by trainees within Responsible Conduct of Research and other classroom settings using a blended format in which some materials are viewed independently online and others are used by groups in class. The total instruction time will be 2-4 hours. As a result of this training, knowledge of why and how to perform cell authentication will improve and research reproducibility problems involving cell lines will decrease. This project will save millions of dollars in wasted research expenditures and decrease translation time from bench to clinic to bedside.